Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Decades of satellite monitoring reveal Antarctic ice loss

14.06.2018

New research review provides insights into the continent's response to climate warming

Scientists from the University of Maryland, the University of Leeds and the University of California, San Diego, have reviewed decades of satellite measurements to reveal how and why Antarctica's glaciers, ice shelves and sea ice are changing.


Sea ice floes gather in the Southern Ocean near Antarctica. A new research review integrates decades of satellite measurements to reveal how and why Antarctica's glaciers, ice shelves and sea ice are changing.

Credit: Sinéad Farrell


Icebergs float in the Southern Ocean near Antarctica. A new research review integrates decades of satellite measurements to reveal how and why Antarctica's glaciers, ice shelves and sea ice are changing.

Credit: Sinéad Farrell

Their report, published in a special Antarctica-focused issue of the journal Nature on June 14, 2018, explains how ice shelf thinning and collapse have triggered an increase in the continent's contribution to sea level rise. The researchers also found that, although the total area of sea ice surrounding Antarctica has shown little overall change since the advent of satellite observations, mid-20th century ship-based observations suggest a longer-term decline.

"Antarctica is way too big to survey from the ground, and we can only truly understand the trends in its ice cover by looking at the continent from space," said Andrew Shepherd, a professor of Earth observation at the University of Leeds' School of Earth and Environment and the lead author of the review.

In West Antarctica, ice shelves are being eaten away by warm ocean water, and those in the Amundsen and Bellingshausen seas have thinned by as much as 18 percent since the early 1990s. At the Antarctic Peninsula, where air temperatures have risen sharply, ice shelves have collapsed as their surfaces have melted. Altogether, 34,000 square kilometers (more than 13,000 square miles) of ice shelf area has been lost since the 1950s.

More than 150 studies have tried to determine how much ice the continent is losing. The biggest changes have occurred in places where ice shelves--the continent's protective barrier--have either thinned or collapsed.

"Although breakup of the ice shelves does not contribute directly to sea-level rise--since ice shelves, like sea ice, are already floating--we now know that these breakups have implications for the inland ice," said Helen Fricker, a professor of glaciology at Scripps Institution of Oceanography at UC San Diego and a co-author of the review. "Without the ice shelf to act as a natural buffer, glaciers can flow faster downstream and out to sea."

In the Amundsen Sea, for example, ice shelf thinning of up to 6 meters (nearly 20 feet) per year has accelerated the advance of the Pine Island and Thwaites glaciers by as much as 1.5 kilometers (nearly 1 mile) per year. These glaciers have the potential to raise sea levels by more than a meter (more than three feet) and are now widely considered to be unstable.

Meanwhile, satellite observations have provided an increasingly detailed picture of sea ice cover, allowing researchers to map the extent, age, motion and thickness of the ice. The combined effects of climate variability, atmosphere and ocean circulation, and even ice shelf melting have driven regional changes, including reductions in sea ice in the Amundsen and Bellingshausen seas.

"The waxing and waning of the sea ice controls how much sunlight is reflected back to space, cooling the planet," said Sinéad Farrell, an associate research scientist at UMD's Earth System Science Interdisciplinary Center and a co-author of the review. "Regional sea ice loss impacts the temperature and circulation of the ocean, as well as marine productivity."

Other findings covered by the research review include:

  • The Antarctic continent is covered by about 15.5 million square kilometers (nearly 6 million square miles) of ice, which has accumulated over thousands of years through snowfall. The weight of new snow compresses the older snow below it to form solid ice.
  • Glaciers flowing down the ice sheet spread under their own weight as they flow toward the ocean and eventually lose contact with the bedrock, forming about 300 floating ice shelves that fringe the continent. These shelves contain about 10 percent--or 1.5 million square kilometers (nearly 600,000 square miles)--of Antarctica's ice.
  • In the Southern Ocean around Antarctica, sea ice expands and contracts as ocean water freezes and melts throughout the year. The sea ice covers an area of 18.5 million square kilometers (more than 7 million square miles) in winter and grows to about 1 meter (more than 3 feet) thick.
  • It is estimated that there is enough water locked up in Antarctica's ice sheet to raise global sea levels by more than 50 meters (more than 164 feet).

New and improved satellite missions, such as Sentinel-3, the recently launched Gravity Recovery and Climate Experiment Follow-On (GRACE-FO) and the eagerly awaited ICESat-2, will continue to give researchers more detailed insights into the disappearance of Antarctic ice.

###

This release was adapted from text provided by the University of Leeds.

The research review, "'Trends and connections across the Antarctic cryosphere," Andrew Shepherd, Helen Fricker and Sinéad Farrell, was published in the June 14, 2018 issue of the journal Nature.

This work was supported by the U.K. Natural Environment Research Council's Centre for Polar Observation and Modelling (Award No. cpom300001), NASA (Award No. 80NSSC17K0006), the U.S. National Oceanic and Atmospheric Administration (Award No. NA14NES4320003), the European Space Agency's Climate Change Initiative, and the U.K. Royal Society. The content of this article does not necessarily reflect the views of these organizations.

Media Relations Contacts:

The University of Leeds: Press office, +44(0)113 343 4036, pressoffice@leeds.ac.uk

UMD: Matthew Wright, 301-405-9267, mewright@umd.edu

University of Maryland
College of Computer, Mathematical, and Natural Sciences
2300 Symons Hall
College Park, MD 20742
http://www.cmns.umd.edu

About the College of Computer, Mathematical, and Natural Sciences

The College of Computer, Mathematical, and Natural Sciences at the University of Maryland educates more than 9,000 future scientific leaders in its undergraduate and graduate programs each year. The college's 10 departments and more than a dozen interdisciplinary research centers foster scientific discovery with annual sponsored research funding exceeding $175 million.

Media Contact

Matthew Wright
mewright@umd.edu
301-405-9267

 @UMDRightNow

http://www.umdrightnow.umd.edu/ 

Matthew Wright | EurekAlert!
Further information:
https://cmns.umd.edu/news-events/features/4156
http://dx.doi.org/10.1038/s41586-018-0171-6

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

Smallest transistor worldwide switches current with a single atom in solid electrolyte

17.08.2018 | Physics and Astronomy

Robots as Tools and Partners in Rehabilitation

17.08.2018 | Information Technology

Climate Impact Research in Hannover: Small Plants against Large Waves

17.08.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>